In 42 years, Ben will be 3 times as old as he is right now. How old is he right now?
Solution: We can use the given information to write down an equation about Ben's age. Let Ben's age be $b$ In 42 years, he will be $b + 42$ years old. At that time, he will also be $3 b$ years old. Writing this information as an equation, we get: $b + 42 = 3 b$ Solving for $b$ , we get: $2 b = 42$ $b = 21$.